I'm not surprised by this because I have seen many people making the same mistake. Anyway based on my relatives' and friends' experience, here is what I suggest:
If your uncle hasn't done "bibaha darta", then he should do it now and put the wedding date after the date of DV application, which would show that he was single at the time of the application. Then fill the forms as a married person, but do not include the kids.
Then come to the US. As soon as your uncle and aunt get green card here ( which will take some months), apply green card for the kids. Then the USCIS will do DNA tests to verify if the kids are indeed your uncle's. Within 2/3 years of application your cousins will be here in the US.
If your uncle includes all the family members in the application now, then his visa application might be rejected, but this is just my thought.
Last edited: 30-May-13 04:59 PM